Inspecting Manholes with High-Tech Scanner: The SPiDER
The wastewater collection division is continuing its trend of seeking out high-tech solutions for needed maintenance tasks. Most recently, they contracted with a company to inspect 2,000 manholes in Melbourne using wireless manhole scanning. Called the SPiDER (spherical imagery digitally enhanced rendering), this manhole scanner collects millions of three-dimensional points during each manhole scan that provides engineering and survey quality information on the manhole’s condition.
“We’ll get the information from them to send the coating crews out for maintenance of the manholes,” said foreman Butch Burke. “It will show us which ones need to be recoated and which ones have leaks and infiltration.”
Using this high-tech camera system saves time and money. In the past they would have had to send three employees out for each manhole inspection, which would include all the required safety precautions and measures. This process is much less labor intensive, and the camera is immune to the ill effects of sewer gases.
“We’ll get all the information in advance," said maintenance technician Ruben Rosado. "It will help us decide which ones need to be coated without having to send people out to inspect them. We’ll get the GPS location so they will know exactly where it is.”
There are eight cameras on the SPiDER and the technician described it as like standing inside the manhole and looking around. One of the common manhole maintenance issues the cameras often find is that some of the epoxy linings are flaking due to sewer gases and humidity. Once the needs are identified through these inspections, City coating crews will be called to perform maintenance including pressure washing, fixing leaks and applying a cementitious coating.
Burke said the company they work with for the software for its camera vans, Cues, Inc., brought them a demo and they were impressed by its capabilities. However, to buy one of these cameras would cost $300,000 so there is significant savings in having the work done by a contractor. They will spend the next four to five months inspecting the 2,000 manholes identified by the City — hoping to be able to inspect 10 to 15 per day during weekdays.
There are a total of a little more than 5,000 manholes in the system, but the ones selected for inspection this time were lacking detailed information, which this will correct. To complete inspections for the remaining 3,000 manholes, there is a camera van in the 2022 fiscal year budget. It will be equipped to run the SPiDER camera, which can be rented at that time.